Transcript for New Alert: A Record Breaking Measles Outbreak
An old enemy is back the CDC -- issued an urgent new warning about measles are rampant increase in the virus America nearly vanquished. And remember this is a virus that can take lives. ABC's chief medical editor doctor Richard vasser who once led the CDC tells us what the experts are urgently asking families to do tonight. -- Measles is wildly infections spread by coughing. You can catch it from the -- two hours after someone infected was there and tonight it's spreading the new record -- was 280. Cases. The most since the virus was eliminated from the US back in 2018. States affected the biggest outbreak in Ohio. We're the Amish are getting -- Unvaccinated. Some travel to the Philippines on a mission trip catching the virus now families are racing to get the shots. Another outbreak in upscale San Diego. Where parents deliberately avoided vaccination most residents who are training and they're receiving measles pediatricians now on the look -- Trying to spot the telltale rash the extreme fever the cough. Measles is so contagious they put special negative pressure rooms in -- Children's Hospital. To immediately isolate cases as special filter which means there -- any infectious agent. All these cases like the -- outbreak linked to travelers bringing measles here from around the globe giving it to the unvaccinated. The fear. We slide back to the days before vaccinations began in the early 1960s. When measles -- 48000. Americans a year to the hospital. 7000. With seizures in about 500 died. Do you really -- as. He was an extreme pain. Whose parents and being. Are all. Little Murtaza media was only eight months old to young to backs and when measles struck here in New York. He caught -- during a visit to his doctors. In the room where measles patient had -- There were there just before he walked them. In the same room. And that was enough -- that was enough to give a ruthless. So glad he's all right now but get this perspective on this how bad yet so I just talked to the CDC and they're very concerned about this that there are two things they have they want everyone to do. If you're an adult -- -- traveling overseas they want to make sure you've had at least two doses of measles vaccine. If you're unsure go ahead and get -- again it's safe. But -- for everyone here they want to make sure that you and your kids are vaccinated fully and on time. It's to protect you but it's also -- protecting children like that little baby who is too young he had vaccinated. People with immune problems who can't protect themselves it's about protecting our community you don't want to do that anybody else and -- at second. Thousand cases of seizures from measles that's right people think of it is as they ate mild illness -- get over with. But see that's a lot of people who were harmed in many of them permanently all right thank you so much rich.
This transcript has been automatically generated and may not be 100% accurate.